There is a fairly new bi-monthly magazine out called "Diesel Power". Naturally, they have lots of ads from different makers of aftermarket filters. In the current ( or maybe the prior) issue, they dyno tested 3 or 4 of the popular aftermarket filters on a Dodge Ram. NO difference in H.P. Like it was already mentioned, more noise though. WIth a "pumped-up" engine, ( injectors, exhaust, etc.), then maybe the intake might be the weak link. Also, they cautioned that aftermarket filters might not offer the filtration that stock units do, and cause more engine wear. ALso, the filter oil could cause problems with computor sensors. At least as far as Dodge goes, the engineers did a fine job.